What term describes a molecule that stops the action of free radicals?

• A. Enzyme
• B. Antioxidant
• C. Hormone
• D. Mineral

Answer: (B)

Free radicals are unstable molecules that can cause cellular damage by taking electrons from other molecules. An antioxidant is a molecule that stops these actions by donating electrons or otherwise neutralizing the free radicals, halting the damaging chain reactions. This protective role is why substances like vitamins C and E and certain antioxidant enzymes are described as antioxidants. While enzymes, hormones, and minerals all play important roles in the body, they are not defined by this specific function of neutralizing free radicals. Minerals can serve as cofactors for antioxidant enzymes, but the term that names the molecule that directly counteracts free radicals is antioxidant.